The scene of a double fatality on a highway near Nelson has been been examined but it is too early to say whether charges will be laid, police say.
Stephen Anthony Jayes, 41, has been named as one of the victims of the three-vehicle crash on Monday on Tasman's Coastal Highway.
The Nelson man was in a truck carrying scaffolding and died at the scene. Police are yet to name the other person killed in the crash.
The light truck, a 4WD towing a caravan and a rental car collided on State Highway 60, in Redwood Valley between Richmond and Mapua. Police said investigations were continuing, including looking at whether driver error was a factor.
Two Nelson men, aged 28 and 19, who were in the truck, are in Nelson Hospital in a stable condition.
A 63-year-old man American man and a 60-year-old American woman, who were in the rental car, and are both in a stable condition in hospital.
A 65-year-old Christchurch woman, who was in the third vehicle, is in a stable condition in Nelson Hospital.
"Police are working through formal identification of the second person who died at the scene before the name will be released," Senior Sergeant Blair Hall said.
Emergency services did an excellent job freeing multiple people trapped in the vehicles, Mr Hall said.
"The scene was very challenging due to having three vehicles involved. It was a high-speed crash and one of those vehicles was towing a caravan."
He said the serious crash unit had examined the scene but it was was too early to say whether there would be any charges.
Officers had spoken to several witnesses, but would still like to speak to anyone who saw the crash and had not yet talked to police.
"We would also like to view any footage that members of the public may have taken before emergency services have arrived."
Mr Hall said the crash had affected many families, and thanked all those who helped.